COLOGNE, Germany — Two commuter trains collided head-on in southern Germany on Tuesday, killing at least 10 people, injuring several dozen, and raising new questions about the safety and reliability of a rail network in Europe that has been the envy of much of the world.

Stefan Sonntag, a spokesman for the police in Upper Bavaria, where the crash occurred, said the trains had been traveling along the same stretch of track when they slammed into each other shortly before 7 a.m. near Bad Aibling, about 35 miles southeast of Munich. It was not immediately clear why the trains had been on the same track at the same time, he said.

About 50 passengers were severely hurt, and 100 others sustained light injuries, Mr. Sonntag said. The authorities said later that the drivers and conductors of both trains were among those killed. “We haven’t seen such an accident in this region in a very long time, if ever,” Mr. Sonntag said. “It is terrible.”

Rail travel is central to Germany, as it is to many European countries. But particularly here, as it ties together the country’s many regions in a lacework that differs from, for example, the system in France, which is more centralized on Paris, the capital. Although Germany has a vast rail network, trains traveling in opposite directions frequently share tracks in many rural regions.

The crash added to a string of tragedies and scandals over the past year that have tarnished the nation’s reputation for oversight and efficiency, including Volkswagen’s lying about the emissions tests of some of its vehicles, and the crash of a Germanwings jet that was rammed into a French mountainside by a pilot who had suffered from depression.

The circumstances that led to the train collision on Tuesday were unclear, but crashes across Europe in recent years have highlighted weaknesses in the rail network.

Many countries in the region have abandoned government-run monopolies in favor of privately-run rail systems, even as the European Union is spending billions of euros to modernize rail networks.

The result is an increasingly precarious system, with a patchwork of old and new technologies in use at the same time, and with drivers, who are often alone in cars, shouldering more responsibility for safety.

In Germany, the most serious accident since unification was in 1998, when 101 people died in the northern town of Eschede after a high-speed train derailed, crashing into a bridge. Fatal crashes since then have been rare and on a much smaller scale.

Alexander Dobrindt, the federal transportation minister, said at a news conference that Tuesday’s crash had happened on a curve, meaning that the drivers had probably not seen each other.

Mr. Dobrindt, who described the accident as “a terrible catastrophe,” said the trains “must have collided at very high speed” because velocities of up to 100 kilometers per hour, or about 60 miles per hour, were permitted on the stretch where the collision occurred.

He said that two of three data recorders on the two trains had been recovered and that the third would probably be extracted from the wreckage later on Tuesday. He added that any determination about whether the crash was a result of a technical fault or human error could come only after they had been analyzed.

All routes in Germany use a system in which the brakes should be automatically applied when a train goes through a stop signal or enters a section of track that is not clear for transit, Mr. Dobrindt said.

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An aerial view of the crash site near Bad Aibling, around 35 miles southeast of Munich.CreditPeter Kneffel/DPA, via Agence France-Presse — Getty Images

Joachim Herrmann, Bavaria’s interior minister, said at the news conference that it appeared at least one of the trains was off schedule, but that it was not clear why. He added that the collision had prompted him and other Bavarians to recall a crash in nearby Warngau in 1975 that killed about 40 people.

The regional rail provider Meridian, which operated both of the trains in the crash, said in a statement on its website that it was working to help all those involved, and it provided a hotline for the families of those on board.

“The accident is a terrible shock for us,” Bernd Rosenbusch, managing director of Bayerische Oberlandbahn, the parent company of the Meridian line, said in the statement. “We are doing everything possible to help the passengers, their relatives and the rescue workers.” Bayerische Oberlandbahn is owned by the German subsidiary of the French railway conglomerate Transdev.

Images from the scene, published by the local online publication Rosenheim24.de, showed a yellow and blue carriage, its windows smashed, teetering on the railway tracks. Beside it lay shards of glass and mangled pieces of metal.

Rescue helicopters, including from neighboring Austria, and dozens of ambulances were sent to the scene of the crash, which was at a curve in a wooded area by a canal, the public broadcaster Bayerischer Rundfunk said.

In addition to commuters, train passengers at that time usually include children traveling from small villages to schools in larger towns, but schools in Bavaria are on winter break this week.

Some people may have been traveling to Mardi Gras festivities, which are observed in the largely Roman Catholic state, or to the mountains for skiing.

Alison Smale contributed reporting from Berlin.

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